There
are two types of satellite systems in the market today. The first satellite systems were C-band
systems; however, over the last two decades, the introduction and expansion of DTH systems has revolutionized the market.

The first step
in creating the digital satellite system is to raise the satellites.
This requires a launch missile to raise it to a low-earth geosynchronous
orbit (18,000 mph at 22,500 miles). "Geosynchronous" means that the satellite
maintains a constant position relative to the earth. A geosynchronous orbit ensures that
the antenna does not need to be re-positioned. Each DTH satellite has at least 16
transponders, and each transponder has multiple channels possible because of the digital
signal compression and alternately using polarization.

With the
satellites in place, a DTH broadcast requires an Earth station for uplink.
"Uplink" refers to sending data up to the satellite, which then retransmits the
data down (downlink) along a particular angle.

The DTH antennas have a narrow beam width, which means exact pointing
within three degrees is critical. If you are self-installing your antenna, you can get
information on aiming the antenna (based on your zip code and dish type) by clicking on
the link for DISH
Network DTH Systems

There are two
settings required for aiming a round (18") antenna, and three settings required for
using an elliptical (18" x 24") antenna:

The LNB is the component which sits out in front of the antenna on
the LNB arm. It is a signal converter which converts the
Ku-band signal from the satellite to a 3.7 GHz - 4.2 GHz signal which is sent to the cable
outputs on the LNB, using a band pass filter and an
amplifier. Each LNB can only operate on one polarization
setting at a time. Alternate polarization is used to separate adjacent channels to prevent
interference, which is why you need a Dual LNB to view both odd and even channels at the
same time.

The receiver is
connected to the LNB via 75-ohm Coaxial cable and tunes the
radio frequencies to receive and display each channel. For proper operation, the receiver
should have a valid access card and a telephone line installed. The card contains a
microprocessor, which supplies the decoding sequence for the receiver and controls channel
access and billing. The telephone line allows for data update from the service provider
and is required in order to receive pay-per-view events.

The satellites used for DISH Network programming are owned by
EchoStar Corporation. There are four satellite locations (at
61.5º, 110º, 119º, and 148º) and eight satellites,
providing over 500 channels.

Installation is included in the purchase of a DISH Network satellite system.
After you have received your equipment professional installer will install
it for you by appointment. If you prefer to install it yourself, a number of accessories
are available at your local
RadioShack Store.

A device which is connected to and receives the signal from the LNB
via cable and converts it to a standard Audio/Video signal. DTH
receivers have built-in decoders; older C-Band
receivers may require a separate decoder.

A piece of equipment which is launched into orbit for various purposes,
often to receive and/or transmit a particular signal. Many types of satellites,
including those designed to retransmit DTH signals, are placed in geosynchronous
orbits, allowing a satellite antenna to be
positioned to receive the signal without the need for periodic
re-positioning or re-aiming of the antenna.

A device with one input and two or more outputs which splits the signal
into two or more signals, each which has a lower signal strength than the
original signal (unless the splitter includes an amplifier or is part of a splitter/combiner).

Combiner: Used to combine two different signals which operate on
different frequencies (such as from a broadcast antenna output and a satellite
antenna) into a single signal carried on a single cable, to simplify
running the cable from the antenna(s) and the receiver(s).

Splitter: A specialized splitter used to to split the combined signal back
into the two original signals to allow each signal to be connected to the
correct input on the receiver.